Radiofrequency localization of nonpalpable breast cancer in a multicentre prospective cohort study: feasibility, clinical acceptability, and safety.

PURPOSE: In breast conserving surgery, accurate lesion localization is essential for obtaining adequate surgical margins. Preoperative wire localization (WL) and radioactive seed localization (RSL) are widely accepted methods to guide surgical excision of nonpalpable breast lesions but are limited by logistical challenges, migration issues, and legislative complexities. Radiofrequency identification (RFID) technology may offer a viable alternative. The purpose of this study was to evaluate the feasibility, clinical acceptability, and safety of RFID surgical guidance for localization of nonpalpable breast cancer. METHODS: In a prospective multicentre cohort study, the first 100 RFID localization procedures were included. The primary outcome was the percentage of clear resection margins and re-excision rate. Secondary outcomes included procedure details, user experience, learningcurve, and adverse events. RESULTS: Between April 2019 and May 2021, 100 women underwent RFID guided breast conserving surgery. Clear resection margins were obtained in 89 out of 96 included patients (92.7%), re-excision was indicated in three patients (3.1%). Radiologists reported difficulties with the placement of the RFID tag, partially related to the relatively large needle-applicator (12-gauge). This led to the premature termination of the study in the hospital using RSL as regular care. The radiologist experience was improved after a manufacturer modification of the needle-applicator. Surgical localization involved a low learning curve. Adverse events (n = 33) included dislocation of the marker during insertion (8%) and hematomas (9%). The majority of adverse events (85%) occurred using the first-generation needle-applicator. CONCLUSION: RFID technology is a potential alternative for non-radioactive and non-wire localization of nonpalpable breast lesions.

A multicenter prospective cohort study to evaluate feasibility of radio-frequency identification surgical guidance for nonpalpable breast lesions: design and rationale of the RFID Localizer 1 Trial.

BACKGROUND: Breast cancer screening and improving imaging techniques have led to an increase in the detection rate of early, nonpalpable breast cancers. For early breast cancer, breast conserving surgery is an effective and safe treatment. Accurate intraoperative lesion localization during breast conserving surgery is essential for adequate surgical margins while sparing surrounding healthy tissue to achieve optimal cosmesis. Preoperative wire localization and radioactive seed localization are accepted standard methods to guide surgical excision of nonpalpable breast lesions. However, these techniques present significant limitations. Radiofrequency identification (RFID) technology offers a new, nonradioactive method for localizing nonpalpable breast lesions in patients undergoing breast conserving surgery. This study aims to evaluate the feasibility of RFID surgical guidance for nonpalpable breast lesions. METHODS: This multicenter prospective cohort study was approved by the Institutional Review Board of the University Medical Center Utrecht. Written informed consent is obtained from all participants. Women with nonpalpable, histologically proven in situ or invasive breast cancer, who can undergo breast conserving surgery with RFID localization are considered eligible for participation. An RFID tag is placed under ultrasound guidance, up to 30 days preoperatively. The surgeon localizes the RFID tag with a radiofrequency reader that provides audible and visual real-time surgical guidance. The primary study outcome is the percentage of irradical excisions and reexcision rate, which will be compared to standards of the National Breast Cancer Organisation Netherlands (NABON)(≤ 15% irradical excisions of invasive carcinomas). Secondary outcomes include user acceptability/experiences, learning curve, duration and ease of the placement- and surgical procedure and adverse events. DISCUSSION: This study evaluates the feasibility of RFID surgical guidance for nonpalpable breast lesions. Results may have implications for the future localization techniques in women with nonpalpable breast cancer undergoing breast conserving surgery. TRIAL REGISTRATION: Netherlands National Trial Register, NL8019 , registered on September 12th 2019.

A Comprehensive Grading System for a Magnetic Sentinel Lymph Node Biopsy Procedure in Head and Neck Cancer Patients.

A magnetic sentinel lymph node biopsy ((SLN)B) procedure has recently been shown feasible in oral cancer patients. However, a grading system is absent for proper identification and classification, and thus for clinical reporting. Based on data from eight complete magnetic SLNB procedures, we propose a provisional grading system. This grading system includes: (1) a qualitative five-point grading scale for MRI evaluation to describe iron uptake by LNs; (2) an ex vivo count of resected SLN with a magnetic probe to quantify iron amount; and (3) a qualitative five-point grading scale for histopathologic examination of excised magnetic SLNs. Most SLNs with iron uptake were identified and detected in level II. In this level, most variance in grading was seen for MRI and histopathology; MRI and medullar sinus were especially highly graded, and cortical sinus was mainly low graded. On average 82 ± 58 µg iron accumulated in harvested SLNs, and there were no significant differences in injected tracer dose (22.4 mg or 11.2 mg iron). In conclusion, a first step was taken in defining a comprehensive grading system to gain more insight into the lymphatic draining system during a magnetic SLNB procedure.

Breast MRI in patients after breast conserving surgery with sentinel node procedure using a superparamagnetic tracer.

BACKGROUND: A procedure for sentinel lymph node biopsy (SLNB) using superparamagnetic iron-oxide (SPIO) nanoparticles and intraoperative sentinel lymph node (SLN) detection was developed to overcome drawbacks associated with the current standard-of-care SLNB. However, residual SPIO nanoparticles can result in void artefacts at follow-up magnetic resonance imaging (MRI) scans. We present a grading protocol to quantitatively assess the severity of these artefacts and offer an option to minimise the impact of SPIO nanoparticles on diagnostic imaging. METHODS: Follow-up mammography and MRI of two patient groups after a magnetic SLNB were included in the study. They received a 2-mL subareolar dose of SPIO (high-dose, HD) or a 0.1-mL intratumoural dose of SPIO (low-dose, LD). Follow-up mammography and MRI after magnetic SLNB were acquired within 4 years after breast conserving surgery (BCS). Two radiologists with over 10-year experience in breast imaging assessed the images and analysed the void artefacts and their impact on diagnostic follow-up. RESULTS: A total of 19 patients were included (HD, n = 13; LD, n = 6). In the HD group, 9/13 patients displayed an artefact on T1-weighted images up to 3.6 years after the procedure, while no impact of the SPIO remnants was observed in the LD group. CONCLUSIONS: SLNB using a 2-mL subareolar dose of magnetic tracer in patients undergoing BCS resulted in residual artefacts in the breast in the majority of patients, which may hamper follow-up MRI. This can be avoided by using a 0.1-mL intratumoural dose.

A complete magnetic sentinel lymph node biopsy procedure in oral cancer patients: A pilot study.

OBJECTIVES: To assess the feasibility and merits of a complete magnetic approach for a sentinel lymph node biopsy (SLNB) procedure in oral cancer patients. MATERIALS AND METHODS: This study included ten oral cancer patients (stage cT1-T2N0M0) scheduled for elective neck dissection (END). Superparamagnetic iron oxide nanoparticles (SPIO) were administered peritumorally prior to surgery. A preoperative MRI was acquired to identify lymph nodes (LNs) with iron uptake. A magnetic detector was used to identify magnetic hotspots prior, during, and after the SLNB procedure. The resected sentinel LNs (SLNs) were evaluated using step-serial sectioning, and the neck dissection specimen was assessed by routine histopathological examination. A postoperative MRI was acquired to observe any residual iron. RESULTS: Of ten primary tumors, eight were located in the tongue, one floor-of-mouth (FOM), and one tongue-FOM transition. SPIO injections were experienced as painful by nine patients, two of whom developed a tongue swelling. In eight patients, magnetic SLNs were successfully detected and excised during the magnetic SLNB procedure. During the END procedure, additional magnetic SLNs were identified in three patients. Histopathology confirmed iron deposits in sinuses of excised SLNs. Three SLNs were harboring metastases, of which one was identified only during the END procedure. The END specimens revealed no further metastases. CONCLUSION: A complete magnetic SLNB procedure was successfully performed in eight of ten patients (80% success rate), therefore the procedure seems feasible. Recommendations for further investigation are made including: use of anesthetics, magnetic tracer volume, planning preoperative MRI, comparison to conventional technique and follow-up.

Droplet digital polymerase chain reaction for rapid broad-spectrum detection of bloodstream infections.

The droplet digital polymerase chain reaction (ddPCR) is a novel molecular technique that allows rapid quantification of rare target DNA sequences. Aim of this study was to explore the feasibility of the ddPCR technique to detect pathogen DNA in whole blood and to assess the diagnostic accuracy of ddPCR to detect bloodstream infections (BSIs), benchmarked against blood cultures. Broad-range primers and probes were designed to detect bacterial 16S rRNA (and Gram stain for differentiation) and fungal 28S rRNA. To determine the detection limit of ddPCR, 10-fold serial dilutions of E. coli and C. albicans were spiked in both PBS and whole blood. The diagnostic accuracy of ddPCR was tested in historically collected frozen blood samples from adult patients suspected of a BSI and compared with blood cultures. Analyses were independently performed by two research analysts. Outcomes included sensitivity and specificity of ddPCR. Within 4 h, blood samples were drawn, and DNA was isolated and analysed. The ddPCR detection limit was approximately 1-2 bacteria or fungi per ddPCR reaction. In total, 45 blood samples were collected from patients, of which 15 (33%) presented with positive blood cultures. The overall sensitivity of ddPCR was 80% (95% CI 52-96) and specificity 87% (95% CI 69-96). In conclusion, the ddPCR technique has considerable potential and is able to detect very low amounts of pathogen DNA in whole blood within 4 h. Currently, ddPCR has a reasonable sensitivity and specificity, but requires further optimization to make it more useful for clinical practice.